perlcygwin - Perl for Cygwin
This document will help you configure, make, test and install Perl on Cygwin. This document also describes features of Cygwin that will affect how Perl behaves at runtime.
NOTE: There are pre-built Perl packages available for Cygwin and a version of Perl is provided in the normal Cygwin install. If you do not need to customize the configuration, consider using one of those packages.
The Cygwin tools are ports of the popular GNU development tools for Win32 platforms. They run thanks to the Cygwin library which provides the UNIX system calls and environment these programs expect. More information about this project can be found at:
A recent net or commercial release of Cygwin is required.
At the time this document was last updated, Cygwin 1.7.16 was current.
While building Perl some changes may be necessary to your Cygwin setup so that Perl builds cleanly. These changes are not required for normal Perl usage.
NOTE: The binaries that are built will run on all Win32 versions. They do not depend on your host system (WinXP/Win2K/Win7) or your Cygwin configuration (binary/text mounts, cvgserver). The only dependencies come from hard-coded pathnames like /usr/local. However, your host system and Cygwin configuration will affect Perl's runtime behavior (see TEST).
PATH
Set the PATH
environment variable so that Configure finds the Cygwin
versions of programs. Any not-needed Windows directories should be removed or
moved to the end of your PATH
.
If you do not have nroff (which is part of the groff package), Configure will not prompt you to install man pages.
The default options gathered by Configure with the assistance of hints/cygwin.sh will build a Perl that supports dynamic loading (which requires a shared cygperl5_16.dll).
This will run Configure and keep a record:
- ./Configure 2>&1 | tee log.configure
If you are willing to accept all the defaults run Configure with -de. However, several useful customizations are available.
It is possible to strip the EXEs and DLLs created by the build process. The resulting binaries will be significantly smaller. If you want the binaries to be stripped, you can either add a -s option when Configure prompts you,
- Any additional ld flags (NOT including libraries)? [none] -s
- Any special flags to pass to g++ to create a dynamically loaded library?
- [none] -s
- Any special flags to pass to gcc to use dynamic linking? [none] -s
or you can edit hints/cygwin.sh and uncomment the relevant variables near the end of the file.
Several Perl functions and modules depend on the existence of some optional libraries. Configure will find them if they are installed in one of the directories listed as being used for library searches. Pre-built packages for most of these are available from the Cygwin installer.
-lcrypt
The crypt package distributed with Cygwin is a Linux compatible 56-bit DES crypt port by Corinna Vinschen.
Alternatively, the crypt libraries in GNU libc have been ported to Cygwin.
-lgdbm_compat
(use GDBM_File
)
GDBM is available for Cygwin.
NOTE: The GDBM library only works on NTFS partitions.
-ldb
(use DB_File
)
BerkeleyDB is available for Cygwin.
NOTE: The BerkeleyDB library only completely works on NTFS partitions.
cygserver
(use IPC::SysV
)
A port of SysV IPC is available for Cygwin.
NOTE: This has not been extensively tested. In particular,
d_semctl_semun
is undefined because it fails a Configure test
and on Win9x the shm*() functions seem to hang. It also creates
a compile time dependency because perl.h includes <sys/ipc.h>
and <sys/sem.h> (which will be required in the future when compiling
CPAN modules). CURRENTLY NOT SUPPORTED!
-lutil
Included with the standard Cygwin netrelease is the inetutils package which includes libutil.a.
The INSTALL document describes several Configure-time options. Some of these will work with Cygwin, others are not yet possible. Also, some of these are experimental. You can either select an option when Configure prompts you or you can define (undefine) symbols on the command line.
-Uusedl
Undefining this symbol forces Perl to be compiled statically.
-Dusemymalloc
By default Perl does not use the malloc()
included with the Perl source,
because it was slower and not entirely thread-safe. If you want to force
Perl to build with the old -Dusemymalloc define this.
-Uuseperlio
Undefining this symbol disables the PerlIO abstraction. PerlIO is now the default; it is not recommended to disable PerlIO.
-Dusemultiplicity
Multiplicity is required when embedding Perl in a C program and using
more than one interpreter instance. This is only required when you build
a not-threaded perl with -Uuseithreads
.
-Uuse64bitint
By default Perl uses 64 bit integers. If you want to use smaller 32 bit integers, define this symbol.
-Duselongdouble
gcc supports long doubles (12 bytes). However, several additional long double math functions are necessary to use them within Perl ({atan2, cos, exp, floor, fmod, frexp, isnan, log, modf, pow, sin, sqrt}l, strtold). These are not yet available with newlib, the Cygwin libc.
-Uuseithreads
Define this symbol if you want not-threaded faster perl.
-Duselargefiles
Cygwin uses 64-bit integers for internal size and position calculations, this will be correctly detected and defined by Configure.
-Dmksymlinks
Use this to build perl outside of the source tree. Details can be found in the INSTALL document. This is the recommended way to build perl from sources.
You may see some messages during Configure that seem suspicious.
d_eofnblk
Win9x does not correctly report EOF
with a non-blocking read on a
closed pipe. You will see the following messages:
- But it also returns -1 to signal EOF, so be careful!
- WARNING: you can't distinguish between EOF and no data!
- *** WHOA THERE!!! ***
- The recommended value for $d_eofnblk on this machine was "define"!
- Keep the recommended value? [y]
At least for consistency with WinNT, you should keep the recommended value.
The following error occurs because of the Cygwin #define
of
_LONG_DOUBLE
:
- Guessing which symbols your C compiler and preprocessor define...
- try.c:<line#>: missing binary operator
This failure does not seem to cause any problems. With older gcc versions, "parse error" is reported instead of "missing binary operator".
Simply run make and wait:
- make 2>&1 | tee log.make
There are two steps to running the test suite:
- make test 2>&1 | tee log.make-test
- cd t; ./perl harness 2>&1 | tee ../log.harness
The same tests are run both times, but more information is provided when
running as ./perl harness.
Test results vary depending on your host system and your Cygwin configuration. If a test can pass in some Cygwin setup, it is always attempted and explainable test failures are documented. It is possible for Perl to pass all the tests, but it is more likely that some tests will fail for one of the reasons listed below.
UNIX file permissions are based on sets of mode bits for
{read,write,execute} for each {user,group,other}. By default Cygwin
only tracks the Win32 read-only attribute represented as the UNIX file
user write bit (files are always readable, files are executable if they
have a .{com,bat,exe} extension or begin with #!
, directories are
always readable and executable). On WinNT with the ntea CYGWIN
setting, the additional mode bits are stored as extended file attributes.
On WinNT with the default ntsec CYGWIN
setting, permissions use the
standard WinNT security descriptors and access control lists. Without one of
these options, these tests will fail (listing not updated yet):
- Failed Test List of failed
- ------------------------------------
- io/fs.t 5, 7, 9-10
- lib/anydbm.t 2
- lib/db-btree.t 20
- lib/db-hash.t 16
- lib/db-recno.t 18
- lib/gdbm.t 2
- lib/ndbm.t 2
- lib/odbm.t 2
- lib/sdbm.t 2
- op/stat.t 9, 20 (.tmp not an executable extension)
Do not use NDBM_File or ODBM_File on FAT filesystem. They can be built on a FAT filesystem, but many tests will fail:
- ../ext/NDBM_File/ndbm.t 13 3328 71 59 83.10% 1-2 4 16-71
- ../ext/ODBM_File/odbm.t 255 65280 ?? ?? % ??
- ../lib/AnyDBM_File.t 2 512 12 2 16.67% 1 4
- ../lib/Memoize/t/errors.t 0 139 11 5 45.45% 7-11
- ../lib/Memoize/t/tie_ndbm.t 13 3328 4 4 100.00% 1-4
- run/fresh_perl.t 97 1 1.03% 91
If you intend to run only on FAT (or if using AnyDBM_File on FAT), run Configure with the -Ui_ndbm and -Ui_dbm options to prevent NDBM_File and ODBM_File being built.
With NTFS (and no CYGWIN=nontsec), there should be no problems even if perl was built on FAT.
fork() failures in io_* testsA fork() failure may result in the following tests failing:
- ext/IO/lib/IO/t/io_multihomed.t
- ext/IO/lib/IO/t/io_sock.t
- ext/IO/lib/IO/t/io_unix.t
See comment on fork in Miscellaneous below.
Cygwin does an outstanding job of providing UNIX-like semantics on top of Win32 systems. However, in addition to the items noted above, there are some differences that you should know about. This is a very brief guide to portability, more information can be found in the Cygwin documentation.
Cygwin pathnames are separated by forward (/) slashes, Universal Naming Codes (//UNC) are also supported Since cygwin-1.7 non-POSIX pathnames are discouraged. Names may contain all printable characters.
File names are case insensitive, but case preserving. A pathname that contains a backslash or drive letter is a Win32 pathname, and not subject to the translations applied to POSIX style pathnames, but cygwin will warn you, so better convert them to POSIX.
For conversion we have Cygwin::win_to_posix_path()
and
Cygwin::posix_to_win_path()
.
Since cygwin-1.7 pathnames are UTF-8 encoded.
Since cygwin-1.7 textmounts are deprecated and strongly discouraged.
When a file is opened it is in either text or binary mode. In text mode
a file is subject to CR/LF/Ctrl-Z translations. With Cygwin, the default
mode for an open() is determined by the mode of the mount that underlies
the file. See Cygwin::is_binmount(). Perl provides a binmode() function
to set binary mode on files that otherwise would be treated as text.
sysopen() with the O_TEXT
flag sets text mode on files that otherwise
would be treated as binary:
- sysopen(FOO, "bar", O_WRONLY|O_CREAT|O_TEXT)
lseek()
, tell() and sysseek() only work with files opened in binary
mode.
The text/binary issue is covered at length in the Cygwin documentation.
PerlIO overrides the default Cygwin Text/Binary behaviour. A file will
always be treated as binary, regardless of the mode of the mount it lives
on, just like it is in UNIX. So CR/LF translation needs to be requested in
either the open() call like this:
- open(FH, ">:crlf", "out.txt");
which will do conversion from LF to CR/LF on the output, or in the environment settings (add this to your .bashrc):
- export PERLIO=crlf
which will pull in the crlf PerlIO layer which does LF -> CRLF conversion on every output generated by perl.
The Cygwin stat(), lstat() and readlink() functions make the .exe
extension transparent by looking for foo.exe when you ask for foo
(unless a foo also exists). Cygwin does not require a .exe
extension, but gcc adds it automatically when building a program.
However, when accessing an executable as a normal file (e.g., cp
in a makefile) the .exe is not transparent. The install program
included with Cygwin automatically appends a .exe when necessary.
Cygwin processes have their own pid, which is different from the
underlying windows pid. Most posix compliant Proc functions expect
the cygwin pid, but several Win32::Process functions expect the
winpid. E.g. $$
is the cygwin pid of /usr/bin/perl, which is not
the winpid. Use Cygwin::winpid_to_pid()
and Cygwin::winpid_to_pid()
to translate between them.
Under Cygwin, $^E is the same as $!. When using Win32 API Functions,
use Win32::GetLastError()
to get the last Windows error.
Using fork() or system() out to another perl after loading multiple dlls
may result on a DLL baseaddress conflict. The internal cygwin error
looks like like the following:
- 0 [main] perl 8916 child_info_fork::abort: data segment start: parent
- (0xC1A000) != child(0xA6A000)
or:
See http://cygwin.com/faq/faq-nochunks.html#faq.using.fixing-fork-failures It helps if not too many DLLs are loaded in memory so the available address space is larger, e.g. stopping the MS Internet Explorer might help.
Use the perlrebase or rebase utilities to resolve the conflicting dll addresses. The rebase package is included in the Cygwin setup. Use setup.exe from http://www.cygwin.com/setup.exe to install it.
1. kill all perl processes and run perlrebase
or
2. kill all cygwin processes and services, start dash from cmd.exe and run rebaseall
.
chown()
On WinNT chown() can change a file's user and group IDs. On Win9x chown()
is a no-op, although this is appropriate since there is no security model.
File locking using the F_GETLK
command to fcntl() is a stub that
returns ENOSYS
.
Win9x can not rename() an open file (although WinNT can).
The Cygwin chroot() implementation has holes (it can not restrict file
access by native Win32 programs).
Inplace editing perl -i
of files doesn't work without doing a backup
of the file being edited perl -i.bak
because of windowish restrictions,
therefore Perl adds the suffix .bak automatically if you use perl -i
without specifying a backup extension.
Cwd::cwd
Returns the current working directory.
Cygwin::pid_to_winpid
Translates a cygwin pid to the corresponding Windows pid (which may or may not be the same).
Cygwin::winpid_to_pid
Translates a Windows pid to the corresponding cygwin pid (if any).
Cygwin::win_to_posix_path
Translates a Windows path to the corresponding cygwin path respecting the current mount points. With a second non-null argument returns an absolute path. Double-byte characters will not be translated.
Cygwin::posix_to_win_path
Translates a cygwin path to the corresponding cygwin path respecting the current mount points. With a second non-null argument returns an absolute path. Double-byte characters will not be translated.
Cygwin::mount_table()
Returns an array of [mnt_dir, mnt_fsname, mnt_type, mnt_opts].
- perl -e 'for $i (Cygwin::mount_table) {print join(" ",@$i),"\n";}'
- /bin c:\cygwin\bin system binmode,cygexec
- /usr/bin c:\cygwin\bin system binmode
- /usr/lib c:\cygwin\lib system binmode
- / c:\cygwin system binmode
- /cygdrive/c c: system binmode,noumount
- /cygdrive/d d: system binmode,noumount
- /cygdrive/e e: system binmode,noumount
Cygwin::mount_flags
Returns the mount type and flags for a specified mount point. A comma-separated string of mntent->mnt_type (always "system" or "user"), then the mntent->mnt_opts, where the first is always "binmode" or "textmode".
If the argument is "/cygdrive", then just the volume mount settings, and the cygdrive mount prefix are returned.
User mounts override system mounts.
- $ perl -e 'print Cygwin::mount_flags "/usr/bin"'
- system,binmode,cygexec
- $ perl -e 'print Cygwin::mount_flags "/cygdrive"'
- binmode,cygdrive,/cygdrive
Cygwin::is_binmount
Returns true if the given cygwin path is binary mounted, false if the path is mounted in textmode.
Cygwin::sync_winenv
Cygwin does not initialize all original Win32 environment variables. See the bottom of this page http://cygwin.com/cygwin-ug-net/setup-env.html for "Restricted Win32 environment".
Certain Win32 programs called from cygwin programs might need some environment variable, such as e.g. ADODB needs %COMMONPROGRAMFILES%. Call Cygwin::sync_winenv() to copy all Win32 environment variables to your process and note that cygwin will warn on every encounter of non-POSIX paths.
This will install Perl, including man pages.
- make install 2>&1 | tee log.make-install
NOTE: If STDERR
is redirected make install
will not prompt
you to install perl into /usr/bin.
You may need to be Administrator to run make install
. If you
are not, you must have write access to the directories in question.
Information on installing the Perl documentation in HTML format can be found in the INSTALL document.
These are the files in the Perl release that contain references to Cygwin. These very brief notes attempt to explain the reason for all conditional code. Hopefully, keeping this up to date will allow the Cygwin port to be kept as clean as possible.
- INSTALL README.cygwin README.win32 MANIFEST
- pod/perl.pod pod/perlport.pod pod/perlfaq3.pod
- pod/perldelta.pod pod/perl5004delta.pod pod/perl56delta.pod
- pod/perl561delta.pod pod/perl570delta.pod pod/perl572delta.pod
- pod/perl573delta.pod pod/perl58delta.pod pod/perl581delta.pod
- pod/perl590delta.pod pod/perlhist.pod pod/perlmodlib.pod
- pod/perltoc.pod Porting/Glossary pod/perlgit.pod
- Porting/checkAUTHORS.pl
- dist/Cwd/Changes ext/Compress-Raw-Zlib/Changes
- ext/Compress-Raw-Zlib/README ext/Compress-Zlib/Changes
- ext/DB_File/Changes ext/Encode/Changes ext/Sys-Syslog/Changes
- ext/Time-HiRes/Changes ext/Win32API-File/Changes lib/CGI/Changes
- lib/ExtUtils/CBuilder/Changes lib/ExtUtils/Changes lib/ExtUtils/NOTES
- lib/ExtUtils/PATCHING lib/ExtUtils/README lib/Module/Build/Changes
- lib/Net/Ping/Changes lib/Test/Harness/Changes
- lib/Term/ANSIColor/ChangeLog lib/Term/ANSIColor/README README.symbian
- symbian/TODO
- cygwin/Makefile.SHs
- ext/IPC/SysV/hints/cygwin.pl
- ext/NDBM_File/hints/cygwin.pl
- ext/ODBM_File/hints/cygwin.pl
- hints/cygwin.sh
- Configure - help finding hints from uname,
- shared libperl required for dynamic loading
- Makefile.SH Cross/Makefile-cross-SH
- - linklibperl
- Porting/patchls - cygwin in port list
- installman - man pages with :: translated to .
- installperl - install dll, install to 'pods'
- makedepend.SH - uwinfix
- regen_lib.pl - file permissions
- NetWare/Makefile
- plan9/mkfile
- symbian/sanity.pl symbian/sisify.pl
- hints/uwin.sh
- vms/descrip_mms.template
- win32/Makefile win32/makefile.mk
- t/io/fs.t - no file mode checks if not ntsec
- skip rename() check when not check_case:relaxed
- t/io/tell.t - binmode
- t/lib/cygwin.t - builtin cygwin function tests
- t/op/groups.t - basegroup has ID = 0
- t/op/magic.t - $^X/symlink WORKAROUND, s/.exe//
- t/op/stat.t - no /dev, skip Win32 ftCreationTime quirk
- (cache manager sometimes preserves ctime of file
- previously created and deleted), no -u (setuid)
- t/op/taint.t - can't use empty path under Cygwin Perl
- t/op/time.t - no tzset()
- EXTERN.h - __declspec(dllimport)
- XSUB.h - __declspec(dllexport)
- cygwin/cygwin.c - os_extras (getcwd, spawn, and several Cygwin:: functions)
- perl.c - os_extras, -i.bak
- perl.h - binmode
- doio.c - win9x can not rename a file when it is open
- pp_sys.c - do not define h_errno, init _pwent_struct.pw_comment
- util.c - use setenv
- util.h - PERL_FILE_IS_ABSOLUTE macro
- pp.c - Comment about Posix vs IEEE math under Cygwin
- perlio.c - CR/LF mode
- perliol.c - Comment about EXTCONST under Cygwin
- ext/Compress-Raw-Zlib/Makefile.PL
- - Can't install via CPAN shell under Cygwin
- ext/Compress-Raw-Zlib/zlib-src/zutil.h
- - Cygwin is Unix-like and has vsnprintf
- ext/Errno/Errno_pm.PL - Special handling for Win32 Perl under Cygwin
- ext/POSIX/POSIX.xs - tzname defined externally
- ext/SDBM_File/sdbm/pair.c
- - EXTCONST needs to be redefined from EXTERN.h
- ext/SDBM_File/sdbm/sdbm.c
- - binary open
- ext/Sys/Syslog/Syslog.xs
- - Cygwin has syslog.h
- ext/Sys/Syslog/win32/compile.pl
- - Convert paths to Windows paths
- ext/Time-HiRes/HiRes.xs
- - Various timers not available
- ext/Time-HiRes/Makefile.PL
- - Find w32api/windows.h
- ext/Win32/Makefile.PL - Use various libraries under Cygwin
- ext/Win32/Win32.xs - Child dir and child env under Cygwin
- ext/Win32API-File/File.xs
- - _open_osfhandle not implemented under Cygwin
- ext/Win32CORE/Win32CORE.c
- - __declspec(dllexport)
- ext/B/t/OptreeCheck.pm - Comment about stderr/stdout order under Cygwin
- ext/Digest-SHA/bin/shasum
- - Use binary mode under Cygwin
- ext/Sys/Syslog/win32/Win32.pm
- - Convert paths to Windows paths
- ext/Time-HiRes/HiRes.pm
- - Comment about various timers not available
- ext/Win32API-File/File.pm
- - _open_osfhandle not implemented under Cygwin
- ext/Win32CORE/Win32CORE.pm
- - History of Win32CORE under Cygwin
- lib/CGI.pm - binmode and path separator
- lib/Cwd.pm - hook to internal Cwd::cwd
- lib/ExtUtils/CBuilder/Platform/cygwin.pm
- - use gcc for ld, and link to libperl.dll.a
- lib/ExtUtils/CBuilder.pm
- - Cygwin is Unix-like
- lib/ExtUtils/Install.pm - Install and rename issues under Cygwin
- lib/ExtUtils/MM.pm - OS classifications
- lib/ExtUtils/MM_Any.pm - Example for Cygwin
- lib/ExtUtils/MakeMaker.pm
- - require MM_Cygwin.pm
- lib/ExtUtils/MM_Cygwin.pm
- - canonpath, cflags, manifypods, perl_archive
- lib/File/Fetch.pm - Comment about quotes using a Cygwin example
- lib/File/Find.pm - on remote drives stat() always sets st_nlink to 1
- lib/File/Spec/Cygwin.pm - case_tolerant
- lib/File/Spec/Unix.pm - preserve //unc
- lib/File/Spec/Win32.pm - References a message on cygwin.com
- lib/File/Spec.pm - Pulls in lib/File/Spec/Cygwin.pm
- lib/File/Temp.pm - no directory sticky bit
- lib/Module/Build/Compat.pm - Comment references 'make' under Cygwin
- lib/Module/Build/Platform/cygwin.pm
- - Use '.' for man page separator
- lib/Module/Build.pm - Cygwin is Unix-like
- lib/Module/CoreList.pm - List of all module files and versions
- lib/Net/Domain.pm - No domainname command under Cygwin
- lib/Net/Netrc.pm - Bypass using stat() under Cygwin
- lib/Net/Ping.pm - ECONREFUSED is EAGAIN under Cygwin
- lib/Pod/Find.pm - Set 'pods' dir
- lib/Pod/Perldoc/ToMan.pm - '-c' switch for pod2man
- lib/Pod/Perldoc.pm - Use 'less' pager, and use .exe extension
- lib/Term/ANSIColor.pm - Cygwin terminal info
- lib/perl5db.pl - use stdin not /dev/tty
- utils/perlbug.PL - Add CYGWIN environment variable to report
- dist/Cwd/t/cwd.t
- ext/Compress-Zlib/t/14gzopen.t
- ext/DB_File/t/db-btree.t
- ext/DB_File/t/db-hash.t
- ext/DB_File/t/db-recno.t
- ext/DynaLoader/t/DynaLoader.t
- ext/File-Glob/t/basic.t
- ext/GDBM_File/t/gdbm.t
- ext/POSIX/t/sysconf.t
- ext/POSIX/t/time.t
- ext/SDBM_File/t/sdbm.t
- ext/Sys/Syslog/t/syslog.t
- ext/Time-HiRes/t/HiRes.t
- ext/Win32/t/Unicode.t
- ext/Win32API-File/t/file.t
- ext/Win32CORE/t/win32core.t
- lib/AnyDBM_File.t
- lib/Archive/Extract/t/01_Archive-Extract.t
- lib/Archive/Tar/t/02_methods.t
- lib/ExtUtils/t/Embed.t
- lib/ExtUtils/t/eu_command.t
- lib/ExtUtils/t/MM_Cygwin.t
- lib/ExtUtils/t/MM_Unix.t
- lib/File/Compare.t
- lib/File/Copy.t
- lib/File/Find/t/find.t
- lib/File/Path.t
- lib/File/Spec/t/crossplatform.t
- lib/File/Spec/t/Spec.t
- lib/Module/Build/t/destinations.t
- lib/Net/hostent.t
- lib/Net/Ping/t/110_icmp_inst.t
- lib/Net/Ping/t/500_ping_icmp.t
- lib/Net/t/netrc.t
- lib/Pod/Simple/t/perlcyg.pod
- lib/Pod/Simple/t/perlcygo.txt
- lib/Pod/Simple/t/perlfaq.pod
- lib/Pod/Simple/t/perlfaqo.txt
- lib/User/grent.t
- lib/User/pwent.t
Support for swapping real and effective user and group IDs is incomplete.
On WinNT Cygwin provides setuid()
, seteuid()
, setgid()
and setegid()
.
However, additional Cygwin calls for manipulating WinNT access tokens
and security contexts are required.
Charles Wilson <cwilson@ece.gatech.edu>, Eric Fifer <egf7@columbia.edu>, alexander smishlajev <als@turnhere.com>, Steven Morlock <newspost@morlock.net>, Sebastien Barre <Sebastien.Barre@utc.fr>, Teun Burgers <burgers@ecn.nl>, Gerrit P. Haase <gp@familiehaase.de>, Reini Urban <rurban@cpan.org>, Jan Dubois <jand@activestate.com>, Jerry D. Hedden <jdhedden@cpan.org>.
Last updated: 2012-02-08